What power will allow a visible beam?

[Alaskan]

Been in my signiture for two years

 

[Bradford717]

I'd go with an LPC-826, LPC-836 or an LPC-840. These can be pushed to 400 mW and I can see the beam fine at that power or even lower. They are all less than $10.00 each and can be found everywhere on eBay.

The LPC-840 isn't my idea of visible. I am looking for a nice red beam in visible light or at least be able to actually see the beam at night.

Still looking over some of DTR'S 638'S.

 

[Bradford717]

Mitsubishi 500mW 638 Diode :drool:Now that's a visible beam! Love red laser! Nice ***y red beam! Mmmm

 

[dontblindmebro]

In my experience any laser below 100 mW or so (non educated guess) won't be visible without external aid like a fog machine.

The exception is green lasers. My greenie, which I'm estimating to be around 50 mW, is not visible except at night or in a dark room, and even then it's just slightly visible in a dark room if you watch it at a specific angle.

If you look at a chart over the visible spectrum you will see that the eye is most sensitive towards the green wavelength.

 

[diachi]

Mitsubishi 500mW 638 Diode :drool:Now that's a visible beam! Love red laser! Nice ***y red beam! Mmmm

In my experience any laser below 100 mW or so (non educated guess) won't be visible without external aid like a fog machine.

The exception is green lasers. My greenie, which I'm estimating to be around 50 mW, is not visible except at night or in a dark room, and even then it's just slightly visible in a dark room if you watch it at a specific angle.

If you look at a chart over the visible spectrum you will see that the eye is most sensitive towards the green wavelength.

638nm is quite a bit brighter than the 650nm (or is it 660?) from an LPC-826 so that helps. Not to mention the Mitts diode will produce more power.

That said, I'd say that beam shot is either a long exposure or has some fog in the room.

 

[BowtieGuy]

The LPC-840 isn't my idea of visible. I am looking for a nice red beam in visible light or at least be able to actually see the beam at night.

Still looking over some of DTR'S 638'S.

I've got an LPC826 build at 383mW that is quite visible, here's a pic at night with no fog, and no long exposure ( Samsung S7 phone camera).

 

[diachi]

I've got an LPC826 build at 383mW that is quite visible, here's a pic at night with no fog, and no long exposure ( Samsung S7 phone camera).

Nice picture!

Was it that bright in person? I know my S7 really enhances things in the dark, I've taken pictures of the Aurora with mine and it looked a lot brighter on the picture than it did to the eye. No long exposure or anything either, may just have had HDR turned on.

An LPC-826 at that sort of power will definitely have a clearly visible beam at night though.

 

[BowtieGuy]

Hi diachi, that pic is just about how it looked in person; it is in a short tripod sitting close to the ground, maybe that brightens it up, not sure.
This was taken in 'auto' mode, so no HDR was on, I actually take most of my pics while in the auto mode, when using my phone camera.

Edit: the above pic is from my "Conehead" build.

 

[steve001]

For a standard 650 nm red laser, what's the general rule for power necessary to produce a visible beam? I'm not talking a lightsaber, just something that will distinguish it from a dog toy. I'm very skeptical of buying 30mW for a build and being able to see the difference.

That really depends mostly on atmospheric conditions. The other is viewing angle. It's not a simple answer.

 

[paul1598419]

I have an LPC-840 doing 380+ mW that is very visible in even dimly lit areas. It is 650nm, so not the most visible WL, but does just fine regardless.

 

[green lasers rock]

My personal experience with red lasers is that the beam can be fairly visible, but especially with 650nm lasers, the beam is such a dark shade of red that it takes a minute to realize it is even there, if that makes any sense. I would say a 200mw 650nm is as low as I would go and still call the beam fairly visible. Don't expect to see it in anything but complete darkness, or be able to move it around without losing site of it. For that, you need a 635nm. As others have mentioned, some people are far more sensitive to the beams of red lasers, so there is really no way to be sure what will work, and in the right conditions a less powerful red laser can create a fairly visible beam. It is also worth noting that a 200mw 650nm is a great option for pinpointing objects far away, as the non intrusive beam and great divergence make such a red laser clearly visible on even distant targets The great thing about red diodes is their low price point, and it is not the end of the world if your first setup is not satisfactory.

 

[The Green Howards]

I Have a 300mw 620 click style open back red laser from laserpointerpro.com, with the battery fully charged up and pointing at the sky on a clear night you can just make out a faint beam of light.

 

[diachi]

I Have a 300mw 620 click style open back red laser from laserpointerpro.com, with the battery fully charged up and pointing at the sky on a clear night you can just make out a faint beam of light.

...620? As in 620nm? Might want to double check that.

Edit: Oh hey, 9,000 posts.

 

[The Green Howards]

650nm

 

[diachi]

650nm

Makes more sense now! :beer:

 

[green lasers rock]

If your impressed by that laser, get a 638nm. Much more visible color. I wouldn't buy it from laser pointer pro though, they are notorious around these parts. You may even consider building it yourself.